/****************************************************************************
 * Copyright 2009 Huascar A. Sanchez                                        *
 *                                                                          *
 * Licensed under the Apache License, Version 2.0 (the "License");          *
 * you may not use this file except in compliance with the License.         *
 * You may obtain a copy of the License at                                  *
 *                                                                          *
 *     http://www.apache.org/licenses/LICENSE-2.0                           *
 *                                                                          *
 * Unless required by applicable law or agreed to in writing, software      *
 * distributed under the License is distributed on an "AS IS" BASIS,        *
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. *
 * See the License for the specific language governing permissions and      *
 * limitations under the License.                                           *
 ****************************************************************************/
package com.gotobject.filter.predicate;

import static com.gotobject.filter.spi.ExecutionContext.any;

/**
 * @author huascar.sanchez@gmail.com (Huascar A. Sanchez)
 */
public abstract class AbstractPredicate<T> implements Predicate<T> {
    @Override
    public Predicate<T> and(Predicate<? super T> thing) {
        return any(new AndPredicate<T>(this, thing));
    }

    @Override
    public Predicate<T> or(Predicate<? super T> thing) {
        return any(new OrPredicate<T>(this, thing));
    }

    private static class AndPredicate<T> extends AbstractPredicate<T> {
        private final Predicate<? super T> one;
        private final Predicate<? super T> two;

        AndPredicate(Predicate<? super T> one, Predicate<? super T> two) {
            this.one = one;
            this.two = two;
        }

        @Override
        public boolean apply(T thing) {
            return one.apply(thing) && two.apply(thing);
        }

        @Override
        public String toString() {
            return one + " and " + two; 
        }
    }

    private static class OrPredicate<T> extends AbstractPredicate<T> {
        private final Predicate<? super T> one;
        private final Predicate<? super T> two;

        OrPredicate(Predicate<? super T> one, Predicate<? super T> two) {
            this.one = one;
            this.two = two;
        }

        @Override
        public boolean apply(T thing) {
            return one.apply(thing) || two.apply(thing);
        }

        @Override
        public String toString() {
            return one + " or " + two;
        }
    }

}
